So I've been working at a Starbucks in the UK for a few weeks now and it's been going pretty great. I feel like I've settled pretty well into the job and overall enjoy my shifts and co-workers etc.

However I have one main gripe: our store is understaffed and as such our manager is basically trying to work us as many hours as possible. There are typically two of us on an opening and closing shift, and rarely more than 3 of us there at a time in the middle of the day, so it's pretty tiring work.

I'm working 56 hours this week (and did even more last week) and had to put my foot down and refuse working an extra shift on my only day off which pissed off my manager a bit. I've been put on the rota for 56 hours next week too. I don't want to stay at this job if I have to keep working so many hours. I'm really tired and it's affecting my mental health too.

However (outside of my customer service personality lol) I'm a very shy person and not good at confrontation and I don't know how to talk to my manager about this properly. What approach should I take? Thank you in advance guys.